This invention relates to a parts half-mounting prevention connection block capable of positively detecting an incompletely-mounted condition of parts, such as a relay and a fuse, with a simple structure, and the invention also relates to an electric connection box provided with this connection block.
FIG. 5 shows one conventional parts half-mounting prevention connection box.
This connection box 41 comprises a connection box main portion 42, and a cover 43. A plurality of electrical parts 44 such as fuses and relays are mounted on the connection box main portion 42, and abutment piece portions 45 for the electrical parts 44 are formed on and extend downwardly from the cover 43. In case any of the electrical parts 44 is in a half-mounted condition (half-fitted condition), this electrical part 44 projects higher, and when the cover 43 is closed, the corresponding abutment piece portion 45 abuts against this electrical part 44. Therefore, the cover 43 can not be closed, so that the half-mounted condition of the electrical part 44 is detected,
However, this structure has a problem that the cover 43, made of a synthetic resin, is elastically deformed because of its elasticity, and absorbs the projecting height of this half-mounted electrical part 44, so that the precision of the half-mounting detection is lowered.
Therefore, there has been proposed a parts half-mounting prevention connection box 51 (see Patent Literature 1) in which projectable detection members 55 are retainingly mounted on a cover 53 as shown in FIG. 6, and in case any of electrical parts 54 such as fuses is half-mounted on a connection box main portion 52, an abutment portion 55a of the corresponding detection member 55 abuts against this electrical part 54 when the cover 53 is closed, and therefore the retaining of this detection member 55 is canceled, and this detection member 55 projects outwardly from the cover 53, so that this half-mounted condition is detected.
In addition to the above structure, there has been proposed a structure in which when electrical parts such as relays are mounted on a connection box main portion, these electrical parts are locked thereto by respective retaining members provided on the connection box main portion (see, for example, Patent Literature 2).
Patent Literature 1
JP-UM-A-5-41052
Patent Literature 2
JP-UM-6-43318
In the above conventional structure (FIG. 6), however, a half-mounted condition of the electrical parts 54 can not be detected unless the cover 53 is closed, and therefore there have been encountered problems that the electrical part 54 is disengaged from the connection box main portion at a stage before the cover 53 is closed, that the detection precision is lowered when the gap between the cover 53 and each electrical part 54 is large; and that the structure of the cover 53, including the detection members 55, is complicated, so that the cost increases.
In the case of the structure in which the electrical parts are retained on the connection box main portion by the respective retaining members, the fixing of the electrical member can be positively effected, but with respect to the half-mounting of the electrical parts, it must be confirmed whether or not each retaining member has performed the intended retaining function, and much time and labor are required for this confirmation. And besides, a cost and a space are required for providing the retaining members, and this has invited a problem that the structure tends to become bulky and costly.